Both the positive masks—Face of Cleric and Ssserpent Head—are extremely powerful if acquired early on Act 1 and 2. On the negative side: N'loth's Hungry Face remains a fairly minor penalty throughout. But by Act 3, the threat of a Gremlin Visage and the small number of remaining rooms/combats makes a roll increasingly dangerous (especially for a deck avoiding most combats). Therefore, it may be wise to gain the gold (or simply leave) in late acts, especially if your deck is reliant on Attacks.
On higher ascensions, it is almost always a bad idea to trade faces, even when encountering the Trader extremely early. The Ascension 15 modifier makes ? rooms far less valuable, making Ssserpent Head a much more dangerous pick up. The first turn in combat is by far the most important one, so rolling Gremlin Visage can absolutely cripple your setup phase. It also disables relics such as Clockwork Souvenir. Finally, if you are going for Act 4, N'loth's Hungry Face can cause you to be unable to take the Sapphire Key, causing you to lose a big spike of power or even being unable to reach the final act entirely. The chance that you will get Face of Cleric is not worth the overall risk of the event.
It is possible to save scum, by choosing to swap faces and close the game and reopen it if you get a bad face, thus resetting the event. This allows you to see whether the face will be good or bad and avoid the bad face if it happens.
Dialogue[]
Encounter
You walk by an eerie statue holding several masks...
Something behind you softly whispers, "Stop."
You swerve around to face the statue which is now facing you!
On closer inspection, it's not a statue but a statuesque, gaunt man. Is he even breathing?
Eerie Man:"Face. Let me touch? Maybe trade?"
Touch
Eerie Man:"Compensation. Compensation."
Mechanically, he cranes out a neat stack of gold and places it into your pouch.
Eerie Man:"What a nice face. Nice face."
While he touches your face, you begin to feel your life drain out of it!
During this, his mask falls off and shatters. Screaming, he quickly covers his face with all six arms dropping even more masks! Amidst all the screaming and shattering, you escape.
His face was completely blank.
Trade
Eerie Man:"For me? FOR ME? Oh yes.. Yes. Yes.. mmm..."
You see one of his arms flicker, and your face is in its hand! Your face has been swapped.
Cultist Headpiece: You feel more talkative (Neutral Face).
Face of Cleric: Raise your Max HP by 1 after each combat (Good Face).
Gremlin Visage: Start each combat with 1 
Face of Cleric and 
Ssserpent Head—are extremely powerful if acquired early on Act 1 and 2. On the negative side: 
N'loth's Hungry Face remains a fairly minor penalty throughout. But by Act 3, the threat of a 
Gremlin Visage and the small number of remaining rooms/combats makes a roll increasingly dangerous (especially for a deck avoiding most combats). Therefore, it may be wise to gain the gold (or simply leave) in late acts, especially if your deck is reliant on Attacks.
Clockwork Souvenir. Finally, if you are going for Act 4, 
